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As a newcomer to reloading, I've been asking questions and doing my research. And the more I look, the more I feel a bit lost. As of today, I've found 3 different methods for load development: ladder, OCW, and Satterlee. Which method is the best? Simplest? Quickest to obtain the best results? And is there any other method that's better?
David
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Looking up OCW test... just not familiar with it.
https://www.youtube.com/watch?v=hNjtKB3mqiI
It looks like a lot of the same info can be found with both the OCW and Satterlee. I use a Satterlee type test to get me close fast and of the 10+ cartridges i have used this method on, only once has it NOT had fantastic results... but it happens. I just ended up using more data points and doubling up on some charge weights to see if that particular charge has a consistent speed shot to shot. 10 shots isn't the end of the load development, but it does seem to help you get to the fine tuning speed really fast. Apparently without knowing it i used components of the OCW method in my fine tuning for final load after narrowing it down to 3 charges with the Satterlee test.
One thing i like about the Satterlee test is that i can do the first 10 shots without having to go to the range. I can shoot down into a small gravel pit behind the house with a chrono and not have to set up a target. When i identify a node i pick 3 charges and load 5 of each and shoot them since it is 20 minutes drive each direction to the range and back it works pretty easily to get a load done in a day this way.
I've been reloading for may years and have over 53,000 rounds on my completed list.
I don't want to rain on your parade but I'm not so sure it is all that simple.
First, all three methods are based upon the assumption that the shooter has no impact on the results that allow one to conclude what works best.
Without shooting from a fixture for every shot, that assumption is questionable.
Before I eliminated my shooter induced variations, I could never repeat the results of a ladder test, because my variations caused more change than adjustments in the powder charges.
When I was foolish enough to assume that my first results meant anything, like declaring victory after shooting one group, i was deceiving myself.
Today, I use the standard deviation among at least 10 groups of the same basic load to determine if I can even make a conclusion.
If the SD is too large, the variation is masking any effect and no conclusion can be made.
If shooter induced variation is greater than the effect of changing charge weight or shooting multiple shots into groups of consistent size, the variation caused by the shooter will often exceed the variation caused by the variables being injected to determine the best load. That means no conclusion as to the effect is possible.
The existence of excessive 'shooter induced variation' just about nullifies any ability to conclude anything using the ladder, Satterlee or OCW methods unless the shooter has learned to eliminate those variations. Unfortunately, most shooters I come in contact with refuse to recognize that they are the source of most of the inaccuracy.
And if your reloading skills are not honed somewhat by experience, the velocity variations created may be more from round to round than the normal variation caused by the powder/primer burn rate variations that yield a 5 to 7 fps standard deviation that even the most practiced reloaders will observe. Reloading induced variations, while not a severe as shooter induced variations, still make conclusions difficult to determine.
Personally, I have graduated to the Optimum Barrel Time or Exit Time method and find it the most efficient in finding an optimum accuracy load.
With one of my most accurate rifles, I experimented and found that the technique worked after I discovered how to keep the variables to a minimum.
But it took me over a year of very focused improvement actions to get my shooting and reloading techniques to the point I could even see the effect of the exit time reloading technique during my initial experimentation.
I have used that technique on 7 brand new rifles and have achieved excellent results with each within a few loads that were matched to the theoretical exit time for each particular barrel.
However, I couldn't see any effect until I had my standard deviation of groups within a load to less than 0.060 inches (My goal is less than 0.050).
I consider that technique a means to gain the last 10% improvement.
The other techniques you list are workable and many shooters have had success with them.
But now that I have broken the code, I start with the technique that gives me the most accuracy as a starting point.
I hear what you are saying but I have to start with one method. As of right now I'm leaning towards using OCW unless someone tells me that there's a better way to go.Quote:
Originally Posted by CFJunkie
David
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I'm sorry, but you've completely lost me here. What do you mean by "standard deviation of groups within a load..."? SD with firearms normally applies to velocity, and refers to feet per second, not thousandths of an inch in group size. What you said makes no sense to me, please explain in more detail, preferably in words of one syllable or less :o. Thanks.Quote:
Originally Posted by CFJunkie
Dave
Standard Deviation is a statistical calculation of the variation of the items being considered compared to the mean.
It is used to determine the degree of variation for all sorts of measurements, particularly in process control.
Yes, shooters get SD calculated by most chronographs automatically based upon the set of velocities being compared.
But that isn't the only variation that may be useful to shooters when trying to determine what works.
If you take the set of group measurements, you also can calculate the standard deviation to see the degree of variation among the groups and it is a very good indicator of consistency.
What I am saying is that if your group sizes within a set of group related to one load are large, the cause is generally something other than the charge, seating depth, trim length, etc. It is usually caused by shooter induced variation (lack of consistency in set up is the most contributing cause).
If you don't have a chronograph it is more difficult because you cannot determine what is ammo error, shooter error or rifle error.
Using a chronograph you can at least see if the load is consistent, regardless of group size.
I also am a champion of a 'control' group using something like Federal Gold Medal Match or Black Hills match ammo. If you cannot shoot less than MOA with those you have a shooting or rifle problem.
With a chrono I load from min to max (or 2.0gn below max to max) in 0.1gn steps. Then plot to find a 'flat spot' in the curve. If you do not get a good curve (a lot of peaks and valleys) then your reloading procdure is at fault, either in powder load, case variance, bullet weight variance, etc. As someone else pointed out to me a long time ago, usually the best load is about 200fps below book max.
Once you are below MOA consistently, then fine tune. Case prep (especially neck tension), exact powder charges, bullet runout, overall length (jump to lands). Bullet selection is important at this point as well. Some bullets are more accurate than others, and they usually cost a lot more as well.
The key is to change one thing at a time and observe the result. Lots of variables so control as much as you can.
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OCW is pretty good at reducing shooter input if you use the round robin group shooting.
That said to really find a long range load, I think you really have to do a ladder load to find pressure signs, then use OCW to find the place where SD is minimized, then run OCW or even just start at max length and shoot 5 shot groups back every 0.005” until you get a great group. Max length can be mag length, some relation to the lands, some relation to the amount of shank in the case or something else. Berger has a method too using more of an OCW methodology. I wouldn’t argue with going that way either.
All that said, OCW can get you a good pretty good load on its own. Seems like OCW always gets me a good load, but not necessarily the best.
Quote:
Originally Posted by nksmfamjp
For the layman i think this encapsulates a good philosophy. Others hit on it also. Seating depth does help with exit time and is the regular guys way of finding the node.
Junkie is an accomplished shooter, his input is at the next level.